What is a logic model?

A logic model is a visualisation of how a service or programme works, detailing the resources and activities that are needed to make it happen and what is expected as a result. It aids evaluation by identifying the steps of implementation that need to be evidenced and what outputs and outcomes are expected to be seen. This can help to identify data that needs collecting and evaluation questions that are helpful to ask. 

View a brief video guide to Logic Models

Why do I need a logic model?

Logic models help with understanding and explaining the structure and aims of a service and they underpin all robust evaluations of services. You will need a logic model to develop a robust evaluation plan and establish data requirements to support monitoring and evaluation. 

Key ingredients

Need

This details the problem that you are trying to address through your service. It should draw from the work done on your needs assessment and community readiness work and so include who you are targeting and why. 

Inputs

This details all of the things needed to run the service, including the staff, venues/spaces, IT equipment, promotional materials and any other relevant resources.

Activities

This details all of the key activities that take place as part of delivery of the service and should relate to all of the inputs you’ve listed. Activities might include things like engagement activities, triage of referrals, assessments of participants, support planning, reminders, home visits or appointments etc. Details of frequency, duration etc should also sit here.

Outputs

Outputs are often confused with outcomes but are very different. Outputs are measurable things that allow us to demonstrate that the activities in our logic model are taking place. It might include things like the number of people referred, the number of assessments completed, the number of people who receive a support plan, the number of people receiving a reminder, the number of people receiving a home visit and/or the number of home visits made etc.  

Outcomes

Outcomes tell us about what’s changed as a result of the activities in our logic model and these should align with what you set out in your Theory of Change. It’s helpful to think about short term, medium term, and long term outcomes.

How to develop a logic model

If you are using a model for your service that has been adopted from elsewhere then there may be an existing logic model that can be adapted to your context. It’s worth checking before you start.

Important tips:

• Logic models have a standard structure meaning you can use the same template for every service. 
• As with a Theory of Change, producing a logic model is not a solo task. It’s helpful to involve the service manager, someone with knowledge of service level data, and whoever will be responsible for the evaluation. 
• It can be difficult to know how much detail to include. Be specific and consider whether someone else could pick up your logic model and replicate your service with based on the information you’ve provided. If no, then more detail is needed.  
• The sections of the logic model are connected – there should be a logical thread that moves you from your inputs all the way to your outputs and outcomes.   

Here you can see an example logic model that was used in the planning and evaluation of the HAPPY perinatal parenting project delivered as part of Better Start Bradford.